PROJECT SUMMARY Shoulder pain following stroke is a major rehabilitation problem affecting approximately 60% of moderate to severely impaired stroke survivors. While many treatments for HSP have been proposed, most do not result in long-term relief of pain. Our long-term goal is to develop a therapeutic intervention to reduce pain related to HSP. In a systematic review of randomized controlled trials, intramuscular peripheral nerve stimulation (PNS), developed by our research group, was the only treatment to provide long-term relief of pain for those with HSP. Our recent pilot RCT compared PNS to physical therapy (PT) and 67% vs. 25% of participants experienced successful pain relief (i.e., ? 2-pt or 30% reduction) from PNS and PT, respectively. Although PNS produced better outcomes than PT, there was still a large percentage of non-responders (50%) in the study. Furthermore, amongst responders, pain relief was incomplete in 63% of the PNS group and 100% in the PT group. Yet, both treatments did produce pain relief in a significant number of participants. Thus, a complementary, multimodal treatment of PNS + PT may increase the percentage of patients who experience significant pain relief and will produce a greater reduction in pain than with PNS or PT alone. The primary objective of this study is to determine if multimodal treatment of HSP with PNS + PT is more efficacious for pain relief than PNS or PT alone. The secondary objective is to investigate mechanisms of pain reduction by PNS and PT. In order to accomplish these objectives, the investigators designed a multi-site, placebo controlled, double-blinded RCT to determine if multimodal treatment of HSP with PNS + PT is more efficacious for pain relief than PNS or PT alone. Measures of pain, pain interference with ADLs, QoL, shoulder biomechanics (shoulder abduction torque, shoulder kinematics, and Fugl-Meyer score), and measures of central sensitization (pain thresholds, secondary hyperalgesia, and temporal summation) will be measured. Participants will be followed for a total of 24 weeks after treatment has concluded.